In order to effectively suppress the harm of vibration and noise, vibration control technology has been widely studied and applied. The so-called vibration control is to take measures in design or installation to control the vibration of equipment and system, and to control the vibration intensity of equipment and system within the allowable range. If the object that generates the exciting force is called the vibration source body, and the object that requires reducing the vibration intensity is called the vibration absorber. According to the different vibration control mechanisms, the methods of vibration control can be divided into three categories:
(1) Vibration reduction
The control method of reducing the vibration of the system by consuming the vibration energy of the vibration source is called vibration reduction
. For example, when designing automobile tyres, the influence of balanced mass should be fully considered to reduce the exciting force caused by unbalanced mass or to reduce diesel engines by improving fuel injection parameters, improving fuel quality and increasing intercooling. Vibration also occurs by reducing the windward area of bridges and building structures to reduce the wind resistance of buildings, so as to suppress the occurrence of vibration. These are examples of the application of vibration reduction technology in reality.
(2) Vibration isolation
Vibration isolation is a control method to reduce the system vibration by controlling the transmission of vibration. That is to say, the effect of vibration on the vibration absorber can be reduced by adding a vibration isolator between the vibration source and the vibration absorber. The commonly used vibration isolators in practical engineering include metal spring isolators, wire rope isolators, rubber isolators, air spring isolators, hydraulic dampers, gas-liquid combination dampers, etc.
(3) Vibration attenuation (or vibration absorption)
The control method of reducing the vibration of the system by transferring the energy of the vibration system is called vibration attenuation or vibration absorption. In other words, the vibration absorber is added to the exciting body, and the interaction between the vibration absorber and the vibration absorber absorbs the energy of the vibration system, so as to reduce the vibration intensity of the vibration absorber. For example, the high damping vibration absorbing material installed on the wall of the pipe, etc.